Curiosity Rover: Zapping Mars, One Laser Shot At A Time

December 6, 2013

Image Caption: The rock "Ithaca" shown here, with a rougher lower texture and smoother texture on top, appears to be a piece of the local sedimentary bedrock protruding from the surrounding soil in Gale Crater. NASA's Curiosity Mars rover used its Mast Camera (Mastcam) to take this image during the 439th Martian day, or sol, of Curiosity's work on Mars (Oct. 30, 2013). Credit: NASA/JPL-Caltech/MSSS [ Larger Image ]

NASA’s Curiosity Mars rover has fired the shot heard round the solar system — 100,000 shots, to be exact. The rover has fired the laser it uses as one way to check which chemical elements are in rocks and soils 100,000 times.

One of a series of 300 used to investigate 10 locations on a rock called “Ithaca,” the 100,00th shot took place this past October. The shots were at a distance of 13 feet, 3 inches from the laser and telescope on the rover’s mast. The infrared laser is used by the Chemistry and Camera (ChemCam) instrument to excite material in a pinhead-sized spot on the target into a glowing, ionized gas, called plasma. ChemCam then uses the telescope to observe the spark and analyzes the spectrum of light to identify the elements in the target.

“Passing 100,000 laser shots is terribly exciting and is providing a remarkable set of chemical data for Mars,” said ChemCam co-investigator Horton Newsom of the University of New Mexico, Albuquerque.

By the beginning of December, ChemCam has fired its laser more than 102,000 times, assessing more than 420 rock or soil targets. A spectrum of data has been returned to Earth with virtually every shot. The majority of targets are zapped at several points with 30 laser pulses at each point. More than 1,600 images taken by the ChemCam’s remote micro-imager camera have also been returned to Earth.

Information is being mined from ChemCam by an international team of scientists and students to document the diversity of materials on the surface inside Mars’ Gale Crater and the geological processes that formed them. “These materials include dust, wind-blown soil, water-lain sediments derived from the crater rim, veins of sulfates and igneous rocks that may be ejecta from other parts of Mars,” Newsom said.

Each pulse of the laser delivers more than a million watts of power for approximately five one-billionths of a second. Laser-induced breakdown spectroscopy, the technique used by ChemCam, has been used to assess composition of targets in other extreme environments, such as inside nuclear reactors and on the sea floor. Experimental applications of laser-induced breakdown spectroscopy have included environmental monitoring and cancer detection. Using the Curiosity rover, NASA’s Mars Science Laboratory Project is the first mission to use this technique on another planet.

Curiosity’s science payload includes ChemCam and 9 other instruments. ChemCam was developed by the US Department of Energy’s Los Alamos National Laboratory in partnership with scientists and engineers funded by the French national space agency, CNES, the University of Toulouse and research agency, CNRS. Curiosity is managed by NASA’s Jet Propulsion Laboratory (JPL).

Image 2 (below): Since landing on Mars in August 2012, NASA’s Curiosity Mars rover has fired the laser on its Chemistry and Camera (ChemCam) instrument more than 100,000 times at rock and soil targets up to about 23 feet (7 meters) away. This mosaic of images from ChemCam’s remote micro-imager camera show the rock, called “Ithaca,” that received the 100,000th zapping, and 299 others. The scale bar at upper right is 1 centimeter (0.4 inch). The target was 13 feet, 3 inches (4.04 meters) from the top of Curiosity’s mast, where the laser and remote micro-imager are mounted, when the rock was inspected during the 439th Martian day, or sol, of the rover’s work on Mars (Oct. 30, 2013). Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/UNM